Jet propulsion unit condition indicator

Abstract

A number of embodiments of jet-propelled watercraft embodying a combined jet propulsion unit and propulsion unit condition sensor. The condition sensor is contained within the outer housing of the jet propulsion unit and may be formed either in the grilled inlet opening, the water inlet portion, the straightening vane portion, or the discharge nozzle portion.

I claim: 
     
       1. A combined water jet propulsion unit and condition sensor and indicator, said water jet propulsion unit being comprised of a water inlet housing portion defining a water inlet opening and a water flow path, an impeller housing rotatably journalling an impeller for pumping water through said water inlet housing portion, and a discharge nozzle portion through which water pumped by said impeller is discharged for providing a propulsive force to an associated watercraft, a propulsion unit cavitation sensor mounted in one of said housing portions for providing a signal indicating that said propulsion unit is operating in a condition of cavitation and a condition indicator for receiving a condition signal from said condition sensor and displaying said condition to an operator of a watercraft powered by said water jet propulsion unit. 
     
     
       2. A combined water jet propulsion unit and condition sensor as defined in claim 1, wherein the propulsion unit condition sensor comprises a pressure sensor for providing a pressure signal indicative of water flow. 
     
     
       3. A combined water jet propulsion unit and condition sensor as defined in claim 2, wherein the pressure sensor comprises a tube for generating a venturi vacuum signal. 
     
     
       4. A combined water jet propulsion unit and condition sensor as defined in claim 1, wherein the propulsion unit condition sensor is disposed in the water inlet housing portion. 
     
     
       5. A combined water jet propulsion unit and condition sensor as defined in claim 4, further including a grilled opening across the water inlet opening and wherein the propulsion unit condition sensor is carried by the grilled opening. 
     
     
       6. A combined water jet propulsion unit and condition sensor as defined in claim 5, wherein the propulsion unit condition sensor is disposed within one of the slats separating the grilled openings. 
     
     
       7. A combined water jet propulsion unit and condition sensor as defined in claim 6, wherein the output from the signal propulsion unit condition sensor is transmitted through the underside of the grilled opening. 
     
     
       8. A combined water jet propulsion unit and condition sensor as defined in claim 7, wherein the condition signal is transmitted out of one of the ends of the grilled openings. 
     
     
       9. A combined water jet propulsion unit and condition sensor as defined in claim 7, wherein the propulsion unit condition sensor comprises a pressure sensor for providing a pressure signal indicative of water flow. 
     
     
       10. A combined water jet propulsion unit and condition sensor as defined in claim 9, wherein the pressure sensor comprises a tube for generating a venturi vacuum signal forge. 
     
     
       11. A combined water jet propulsion unit and condition sensor as defined in claim 4, wherein the propulsion unit condition sensor is disposed in the water inlet duct. 
     
     
       12. A combined water jet propulsion unit and condition sensor as defined in claim 11, wherein the propulsion unit condition sensor comprises a pressure sensor for providing a pressure signal indicative of water flow. 
     
     
       13. A combined water jet propulsion unit and condition sensor as defined in claim 12, wherein the pressure sensor comprises a tube for generating a vacuum signal. 
     
     
       14. A combined water jet propulsion unit and condition sensor as defined in claim 1, wherein the propulsion unit condition sensor is formed in the jet propulsion unit housing to the rear of the impeller. 
     
     
       15. A combined water jet propulsion unit and condition sensor as defined in claim 14, wherein the propulsion unit condition sensor is provided in the area immediately behind the impeller. 
     
     
       16. A combined water jet propulsion unit and condition sensor as defined in claim 15, wherein there are provided a plurality of straightening vanes in the impeller housing portion to the rear of the impeller and wherein the condition sensor is disposed in the straightening vane area. 
     
     
       17. A combined water jet propulsion unit and condition sensor as defined in claim 16, wherein the propulsion unit condition sensor comprises a pressure sensor for providing a pressure signal indicative of water flow. 
     
     
       18. A combined water jet propulsion unit and condition sensor as defined in claim 17, wherein the condition sensor comprises a tube for generating a vacuum signal. 
     
     
       19. A combined water jet propulsion unit and condition sensor as defined in claim 14, wherein the propulsion unit condition sensor is disposed in the discharge nozzle housing portion. 
     
     
       20. A combined water jet propulsion unit and condition sensor as defined in claim 19, wherein the propulsion unit condition sensor comprises a pressure sensor for providing a pressure signal indicative of water flow. 
     
     
       21. A combined water jet propulsion unit and condition sensor as defined in claim 20, wherein the pressure sensor comprises a tube for generating a vacuum signal. 
     
     
       22. A combined water jet propulsion unit and condition sensor and indicated as set forth in claim 1, in combination with a watercraft having a hull propelled by said water jet propulsion unit, an engine carried by said hull for driving said water jet propulsion unit, a rider's area in said hull, said condition indicator being mounted in said hull in said rider's area. 
     
     
       23. A combined watercraft as set forth in claim 22, wherein the rider's area defines a control for operation by a rider and wherein the condition indicator is juxtaposed to said control. 
     
     
       24. A combined watercraft as set forth in claim 23, wherein the rider's area is provided with a straddle-type seat on which a rider/operator may be seated therein, the condition indicator and control is disposed forwardly of said seat. 
     
     
       25. A combined water jet propulsion unit and condition sensor comprised of a water inlet housing portion defining a grilled water inlet opening and a water flow path, an impeller housing rotatably journalling an impeller for pumping water through said water inlet housing portion, and a discharge nozzle portion through which water pumped by said impeller is discharged for providing a propulsive force to an associated watercraft, and a propulsion unit condition sensor mounted within one of the slats separating the grilled openings. 
     
     
       26. A combined water jet propulsion unit and condition sensor as defined in claim 25, wherein the output from the propulsion unit condition sensor is transmitted through the underside of the grilled opening. 
     
     
       27. A combined water jet propulsion unit and condition sensor as defined in claim 26, wherein the condition signal is transmitted out of one of the ends of the grilled openings. 
     
     
       28. A combined water jet propulsion unit and condition sensor as defined in claim 26, wherein the propulsion unit condition sensor comprises a pressure sensor for providing a pressure signal indicative of water flow. 
     
     
       29. A combined water jet propulsion unit and condition sensor as defined in claim 28, wherein the pressure sensor comprises a tube for generating a venturi vacuum signal.